Lubricating compositions



3,242,081 LUBRIICATHNG COMPOSITIUNS Kenneth L. McHugh, Kirkwood, Mo., and John 0. Smith, Swampscott, Mass., assignors to Monsanto Research Corporation, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Apr. 30, 1963, Ser. No. 276,991 13 Claims. (Cl. Z5233.6)

This invention relates to lubricating compositions, and more particularly, provides novel lubricating compositions comprising a base fluid and including as an additive a pibonded organotitanium salt.

For lubrication in the temperature range up to 300 or 400 F., mineral oils can be used effectively. However, design requirements in recent years have demanded the development of lubricants effective under conditions of stress, including higher temperatures such as temperatures in the range of 400 or 500 F. up to 1000 F., as well as stress conditions such as ultra-high pressure loads, exposure to ionizing radiation, and the like. Mineral oil compositions cannot meet this demand, and consequently synthetic base fluids have been developed, such as ester and ether base fluids. These oxygenated base fluids have thermal stability superior to the hydrocarbon fluids such as the mineral oils, but on the other hand, their inherent lubricating properties are generally inferior to those of the mineral oils.

In the lubricant art, experience over the years has gradually accumulated a large fund of information on the effect of various types of additives on mineral oils, and it has been found that lubricity can be enhanced by the combination of additives with mineral oil base fluids. However, in development of lubricant compositions based on synthetic base fluids, it has been established that there is no reliable correlation between activity of an additive in a mineral oil and its activity in one of the synthetic base oils. Thus, there is still an unsatisfied demand for the development of compositions useful as functional fluids and particularly as lubricants in the temperature range of 400 or 500 F. and above.

It is an object of this invention to provide novel functional compositions having improved lubricant properties and useful in the temperature range of 400 or 500 F. and above.

It is a particular object of this invention to provide novel high temperature lubricant compositions having improved extreme pressure and antiwear properties and useful in the temperature range of 400 or 500 F. and above.

These and other objects will become evident on a consideration of the following specification and claims.

It has now been found that combining a base oil of lubricating viscosity, which remains in the liquid phase up to at least about 500 F., with a pi-bonded organotitanium salt having an anion selected from the class consisting of sulfur-containing and chlorine-containing anions provides valuable high temperature lubricant compositions having enhanced lubricating characteristics.

The presently provided lubricant compositions are particularly valuable for the lubrication of moving, frictionally contacting metal surfaces under conditions of stress such as exposure to elevated temperatures, high loads, and the like. It is to be appreciated, however, they are also valuable over a wide spectrum of conditions. As will become evident hereinafter, for example, the presently provided additives decrease the wear exhibited by frictionally contacting metal surfaces even at lower temperatures such as between 100 and 200 F.

In particular, the present invention provides novel, valuable lubricating compositions wherein the stated organotitanium compounds are combined with a polyphenyl ether as the base fluid, such lubricant compositions having sunited States Patent perior lubricity characteristics. The polyphenyl others are known compounds which have found wide application as functional fluids owing to their very good thermal stability, lubricity, and resistance to foam. For example, they have been found to be valuable as hydraulic fluids, heat exchange media, atomic reactor coolants, diffusion pump fluids, lubricants in motor operation generally, and specifically as jet engine lubricants. The stated polyphenyl others may be employed to provide eflective lubrication at operating temperatures as high as 600 F. and above, and with the improved compositions comprising such polyphenyl ethers as base fluids in accordance with this invention, good lubrication can be provided even for heavily loaded metal surfaces in frictional contact at such elevated temperatures. t

In referring to a pi-bonded organotitanium salt, what is meant is a compound of the type sometimes designated a sandwich compound, a cyclomatic compound, or the like. These compounds are of the type containing an organometallic bond similar to the organometallic bond present in the compound known as ferrocene, wherein an organometallic bond is formed between a radical embodying an alicyclic ring of five carbon atoms having the general configuration and unsaturation found in cyclopentadiene. Thus the present organotitanium compounds contain radicals of the cyclopentadienyl configuration, that is, a 5 carbon atom ring, alicyclic in character, in which a first carbon atom is linked by single bonds to each of two more carbon atoms which are in turn linked by double bonds to each of two other carbon atoms which are linked together by a single bond, and each carbon atom has a single substituent (H or a hydrocarbon radical, as will appear hereinafter).

The alicyclic character of the ring structure is essential. For example, both cyclopentadiene and indene contain an alicyclic cyclopentadienyl ring structure. cyclopentadiene has no double bond coordinatively shared with an aromatic ring. Indene has one double bond of the cyc1opentadienyl ring coordinatively shared with an aromatic ring. But in fluorene where each of the double bonds in such ring is coordinatively shared with an aromatic ring, the compound is not alicyclic in character, and fluorene thus does not contain an alicyclic cyclopentadienyl structure.

It has been pointed out that the exact configuration of the electrons in a doubly bonded system, particularly a conjugated 5-membered ring such as the cyclopentadienyl radical, is considered as resonating, and some theorists consider the structural pattern of the ring as being one of shared or distributed bonds, according to which each carbon atom is at all times equivalent to each of the others and all are unsaturated to the same extent. Thus it can be considered, in a rigorous description of the structure, that the bond to metal atom is shared among the five carbon atoms of the ring.

In any case, the formula for the stated compounds useful in the practice of this invention can. be represented as R MX wherein R is a carbocyclic monovalent radical including a S-carbon atom alicyclic ring with two conjugated ethylenic unsaturations, said radical being directly bonded by a ring carbon atom to the metal M, X is an anion and m and n are cardinal numbers of from 1 to 3 and preferably 2.

Substituents of the stated cyclopentadienyl ring attached to the titanium atom in the compounds employed in accordance with this invention may, as stated, he a fused aromatic ring wherein the S-membered alicyclic cyclopentadiene ring is fused to a triply unsaturated aromatic siX-membered ring, as illustration by an indenyl radical. A divalent saturated aliphatic hydrocarbon radical may be attached to two of the cyclopentadienyl ring carbon atoms, providing a polycyclic structure such as the 4,5,6,7-

tetrahydroindenyl radical. Substituents present on the carbocyclic radical including the alicyclic cyclopentadienyl ring will be selected from hydrogen and hydrocarbon radicals, free of aliphatic (ethylenic and acetylenic) unsaturation and containing up to 18 carbon atoms, which may be alkyl and aralkyl such as methyl, Z-methylbutyl, hexyl, decyl, and octadecyl; benzyl, l-phenylethyl, lanaphthylethyl, and so forth; or alicyclic radicals, such as cyclopropyl, cyclohexyl, and l-cyclohexylethyl, or aryl and alkaryl such as phenyl, tolyl, and the like.

Thus referring to the total pi-bonded radicals which may be present in the organotitanium compounds employed in accordance with this invention, illustrative of the presently useful cyclopentadienyl radicals are cyclopentadienyl, methylcyclopentadienyl, methylcyclopentadienyl, dimethylcyclopentadienyl, dipropylcyclopentadienyl, dicyclopropylcyolop-entadienyl, pentylcyclopentadienyl, methyl-t-butylcyclopentadienyl, ethylmethylcyclopentadienyl, cyclohexylcyclopentadienyl, phenylcyclopentadienyl, tolylcyolopentadienyl and so forth.

It will be recalled that each of the several positions on the cyclopentadienyl ring in pi-bonded organometallic compounds is considered to be equivalent, so that specific position-designating notations are unnecessary in designation of cyclopentadienyl radicals. For indenyl radicals, the prefix arcan be employed to indicate positioning of a substituent on the aromatic ring.

Referring to the indenyl radicals including an alicyclic cyclopentadienyl ring which may constitute the organic radical of the organometallic entity in the presently employed titanium compounds, these are illustrated by indenyl, methylindenyl, secbutylindenyl, ar-phenylindenyl, ar(1-phenylbutyl)indenyl, cyclohexylindenyl, phenylindenyl and the like. Hydrogenated indenyl radicals carrying substitutents which can be present in organotitanium compounds within the above-stated definition include for example 4-methyl-4,5,6,7 tetrahydroindenyl, Z-methyl- 4,5,6,7 tetrahydroindenyl, 2-ethyl,4,5,6,7 tetrahydroindenyl and so forth.

The presently employed organotitaniu m compounds containing the above-described carbocyclic radicals are organotitanium salts having an anion containing an element selected from the class consisting of chlorine and sulfur.

In designating these piabonded organotitanium compounds as salts, What is meant is that the compounds are represented by combination of a titanium cation with univalent pi-bonding carbocyclic radicals of the above-stated type and with anions of the above-stated type containing C1 or S, in a number sufficient to satisfy the valence of the titanium ion. These compounds contain radicals corresponding to the anions of ionizable acids and salts, as distinguished from purely organotitanium compounds like dicyclopentadienyltitani-um. As distinguished from the adduct-like organotitanium compounds with electron donor compounds, exemplified by dicyclopentadienyltitanium dicarbonyl, the titanium provides one of the pair of electrons shared with an anion, thus resembling usual inorganic ionizable titanium salts such as titanium tetrachloride. In the pi-bonded organotitanium salts, anion substitueuts are sigma (covalently) bonded, and may be considered as losing ionic character, but their resemblance among pi-bonded origanotitanium compounds to salts and ability to be formally represented as such makes their designation as salts appropriate, and they are accordingly so identified herein. Reference herein to the anionic radicals or anions of these salts are to be understood as applying to the sigma-bonded radicals in the present organotitan-ium compounds.

Referring now to this anionic radical component of the presently employed titanium compounds, these radicals may consist of the stated elements, selected from C1 and S, or of anions including the stated elements as a component. Illustrative of the organotitanium salts of the former group are, for example, dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium pentasulfide, lbis(methylcyclopentadienyl) titanium dichloride, bis(cyclohexylcyclopentadienyl) titanium dichloride, bis(methylcyclopentylcyclopentadienyl) titanium dichloride, bis- (butylcyclopentylcyclopentadienyl) titanium dichloride, bis(dodecylcyclopentadienyl) titanium pentasulfide, bis- (hexadecylcyclopentadienyl) titanium pentasulfide, diindenyl titanium dichloride, bis(ar-methylindenyl) titaniurn dichloride, diindenyl titanium pentasulfide, bis(ar-tbutylindenyl) titanium pentasulfide, bis(benzylcyclopentadienyl) titanium pent-asulfide, bis(tolylcyclopentadienyl) titanium pentasulfide and so forth.

Anions including chlorine and/ or sulfur as constitutents thereof which may be present in other compounds falling within the definition of those useful in practicing this invention include organic and inorganic anions further including such elements as carbon, nitrogen and oxygen. Thus for example, exemplary of an inorganic radical including sulfur is the thiocyanate radical, which may be provided in compounds such as dicyclopentadienyl titanium dithiocyanate, bis(methylcyclopentadienyl) titanium dithiocyanate, dicyclopentadienyl titanium chloride isothiocyanate, dicyclopentadienyl titanium diisothiocyanate, bis(methylcyclopentadienyl) titanium chloride thiocyanate, bis(isooctylcyclopentadienyl) titanium chloride thiocyanate, dicyclopentadienyl titanium monothiocyanate, diindenyl titanium chloride thiocyanate, bis(benzylcyclopentadienyl) titanium dithiocyanate and the like.

The anions in the presently useful titanium salts need not be identical, as will appear from the above-mentioned compounds, for example, and in salts including a plurality of anions, both need not include chlorine, sulfur or both, as long as one does. Thus for example, one such anion may be a chloride ion and the other a different anion, as exemplified by dicyclopentadienyl titanium chloride cyanide, bis(methylcyclopentadienyl) titanium chloride cyanide, bis (butylcyclopentadienyl) titanium chloride cyanide, bis(methylcyclopentadienyl) titanium chloride nitrate, indenyl titanium monochloride monocyanide, bis- (dicyclopentadienyl titanium chloride) oxide and so forth.

Additional anions which may be included in the compounds of the invention comprise those of the organic type, containing carbon, hydrogen and other elements such as chlorine, sulfur, oxygen or the like. For example, the organotitanium compounds may be salts of a haloacetic acid such as trichloroacetic acid. Exemplary of this type of compound are, for example dicyclopenta-dienyl titanium bis(chloroacetate), dicyclopentadienyl titanium bis(trichloroacetate), bis(methylcyclopentadienyl) titanium bis(trichloroacetate), dicyclopentadienyl titanium bis(chlorofluoroacetate) bis- (phenylcyclopentadienyl) titanium bis(chlorofluoroacetate), dicyclopentadienyl titanium bis(perchloropropionate), bis(tx-naphthylcyclopentadienyl) titanium bis(trichlorobutyrate), bis(methylcyclopentadienyl) titanium chloride trichloroacetate, bis(hexadecylcyclopentadienyl) titanium chloride trichloroacetate, diindenyl titanium bis- (trichloroacetate), diindenyl titanium bis(chloroacetate), phenylcyclopentadienyl titanium dibutoxide chloride, decyclopentadienyl titanium dibutoxide chloride, cyclopentadienyl titanium dicyclohexoxide chloride, idenyl titanium dicyclohexoxide chloride, bis(dicyclopentadienyl titanium chloride) oxalate, bis[bis(isopropylcyclopentadienyl) titanium chloride] maleate, cyclopentadienyl titanium bis- (trichloroacetate) chloride, cyclopentadienyl titanium dibutoxide chloride, bis(biphenylylcyclopentadienyl) titanium bis(trichloroacetate).

As will appear hereinafter, certain novel and useful organotitanium compounds can be provided by reaction of a sulfur compound with a halogen compound such as a dicyclopentadienyl titanium bis(trichloroacetate) which appear to have a structure comprising an organic anion including both sulfur and chloride. The reaction product of dicyclopentadienyl titanium bis(trichloroacetate) and sodium sulfide, for example, can be attributed to the structure where (C H is the cyclopentadienyl ring and x is an integer.

Other salts of the dicyclopentadienyl titanium radical including sulfur in an organic anion which may be employed in accordance with this invention are salts of thioglycolic acid and derivatives thereof, such as dicyclopentadienyl titanium bis(mercaptoacetate), bis(methylcyclopentadienyl) titanium bis(mercaptoacetate), bis(arfi-naphthylindenyl) titanium bis(mercap'toacetate), dicyclopentadienyl titanium bis(pentachlorophenylthioace tate) and the like.

Another group of compounds with organic anions containing sulfur which may be present in the compounds employed in the compositions of this invention are the xanthates. Thus for example, presently employed organotitanium compounds may include dicyclopentadienyl titanium bis(ethylxanthate), bis('methylcyclopentadienyl) titanium bis(ethylxanthate), dicyclopentadienyl titanium monochloride mono(ethylxanthate), dicyclopentadienyl titanium bis(butylxanthate) bis(methylcyclopentadienyl) titanium bis(butylxanthate), bis(benzylcyclopentadienyl) titanium bis(ethylxanthate), bis(tolylcyclopentadienyl) titanium bis (ethylxanthate bis (tetradecylcyclopentadienyl) titanium bis(ethylxanthate), dicyclopentadienyl titanium bis(dodecylxanthate), bis(dimethyldindenyl) titanium bis(decylxanthate), cyclopentadienyl titanium bis- (ethylxanthate) diindenyl titanium bis(ethylxanthate) and so forth.

Another group of the useful organotitanium salts with organic anions containing sulfur includes the dithiocarbamates. Illustrative of these are dicyclopentadienyl titanium bis(diethyldithiocarbamate), bis(methylcyclopentadienyl) titanium bis(dibutyldithiocarbamate), bis (hexylcyclopentadienyl) titanium bis(dibutyldithiocarbamate), bis(hexadecylcyclopentadienyl) titanium bis(dibutyldithiocarbamate), bis(phenylcyclopentadienyl) titanium bis(dibutyldithiocarbamate), bis(p sec butylphenylcyclopentadienyl) titanium bis(dibutyldithiocarbamate), bis(biphenylcyclopentadienyl) titanium bis(dibutyldithiocarbamate) dicyclopentadienyl titanium bis(didecyldithiocarbamate) bis ar-phenylindenyl) titanium bis(didecyldithiocarbamate) and the like.

Still another group of acids having anions containing sulfur which may advantageously be present in the titanium compounds employed in accordance With this invention are the 0,0-diesters of dithiophosphoric acid. Thus for example, the presently employed titanium corn-i pounds may include dicyclopentadienyl titanium bis- (diethyldithiophosphate) bis (methylcyclopentadienyl) titanium bis(diethyldithiophosphate) bis[(1-phenylethyl)- cyclopentadienyl] titanium bis(diethyldithiophosphate), bis(acenaphthenylcyclopentadienyl) titanium bis(diethyldithiophosphate) dicyclopentadienyl titanium bis(dibutyldithiophosphate), bis(cyclohexylcyclopentadienyl) titanium (bis(dibutyldithiophosphate), dicyclopentadienyl titanium bis(didecyldithiophosphate),, bis(dimethylcyclopentadienyl) titanium bis(dinonyldithiophosphate), cyclopentadienyl titanium bis(didecyldithiophosphate), diindenyl titanium bis(didecyldithiophosphate), bis(diethy1- cyclopentadienyl) titanium bis(dibutyldithiopohosphate) and so forth.

Preparation of the pi-bonded organotitanium chlorides is generally effected by metathesis of the appropriate cyclopentadienyl alkali metal compound, such as sodium cyclopentadienylide, with the appropriate titanium chloride, as is well known in the art. Metathesis with salts having anions desired to be introduced is usually effective to displace residual chlorine atoms in the resulting pi-bonded *6 organotitanium chlorides, providing other organotitanium salts as employed in the compositions of this invention. Many and indeed most of the salts mentioned above are known compounds; others can be prepared by methods as stated, analogously to the known salts, as will appear from examples as set forth hereinafter. As will appear from those examples, also, describing preparation of certain previously unknown reaction products, crude reaction products of the stated matathesis of a pi-bonded organotitanium chloride with various salts can produce excellent results in improving lubricity of base stocks.

To provide the lubricant compositions of this invention, the organotitanium salts of the nature stated above are combined with a high temperature lubricant base fluid. This will be a base oil lubricating viscosity which remains in the liquid phase at temperatures up to at least about 500 F. In general, the lubricant compositions of this invention Will be designed for lubrication of the moving parts of mechanisms operating in temperature ranges of 400 F. to 700 F. A particularly advantageous base fluid for use under these conditions comprises the above-mentioned polyphenyl ethers.

The polyphenyl ethers employed in the compositions of this invention have from 3 to 7 benzene rings and from 1 t 6 oxygen atoms, with the stated oxygen atoms joining the benzene rings in chains as ether linkages. One or more of the benzene rings in these polyphenyl ethers may be hydrocarbyl substituted. The hydrocarbyl substituents, for thermal stability, must be free of CH and aliphatic CH, so that preferred aliphatic substituents are lower saturated hydrocarbon radicals (l to 6 carbon atoms) like methyl and tert-butyl, and preferred aromatic substituents are .aryl radicals like phenyl, tolyl, t-butylphenyl and a-cumyl. In the latter case, the benzene ring supplied in the hydrocarbyl substituent contributes to the total number of benzene rings in the molecule. Polyphenyl ethers consisting exclusively of chains of from 3 to 7 benzene rings with at least one oxygen atom joining the stated benzene rings in the chains as an ether linkage have particularly desirable thermal stability.

Exemplary of the polyphenyl ethers containing aliphatic carbon which are suitable for base fluids are 3-ring polyphenyl ethers like l-(p-methylphenoxy)-4-phenoxybenzene and 2,4-diphenoxy-l-methylbenzene, 4-ring polyphenyl ethers like bis[p-(p-methylphenoxy)phenyl] ether and bis[p-(p-tert-butylphenoxy)plrenyl] ether, and so forth.

Polyphenyl ethers consisting exclusively of benzene rings and including ether oxygen atoms linking said rings are exemplified by the triphenoxy benzenes and arylsubstituted polyphenyl ethers such as biphenylyl phenoxyphenyl ether, biphenylyloxyphenyl .phenoxyphenyl ether, biphenylyl ether, dibiphenylyloxybenzene, bis (biphenylyloxyphenyl) ether, and the like.

A preferred class of the polyphenyl ethers are those consisting of benzene rings joined in a chain by oxygen atoms as ether linkages between each ring, of the formula C H O(C H O) C H where n is an integer of from 1 to 5.

Examples of the polyphenyl ethers contemplated in this class are the bis(phenoxyphenyl) ethers (4 benzene rings joined in a chain by 3 oxygen atoms), illustrative of which is bis(m-phenoxyphenyl) ether. The bis (phenoxyphenoxy) benzenes are particularly valuable in the present connection. Illustrative of these are m-bis (m-phenoxypfhenoxy benzene, m-bis p-phen oxyphenoxy) benzene, o-bis(o-phenoxyphenoxy)benzene, and so forth. Further, the polyphenyl ethers contemplated herein include the bis(phenoxyphenoxyphenyl) ethers such as his [m(m-phenoxyphenoxy)phenyl] ether, bis[p-(p-phenoxyphenoxy)phenyl] ether, and m-(m-phenoxyphenoxy) phenyl m-(o-phenoxyphenoxy)phenyl ether and the bis (phenoxyphenoxyphenoxy)benzenes such as m-bisLm-(mphenoxyphenoxy) phenoxy] benzene, p-bis p- (m-phenoxyphenoxy)phenoxy]benzene and m bis [m (p phenoxyphenoxy)phenoxy]benzene.

The preferred polyphenyl ethers are those having all their ether linkages in the meta-positions since the allmeta-linked ethers are particularly advantageous because of their wide liquid range and high thermal stability. However, mixtures of the polyphenyl ethers, either isomeric mixtures or mixtures of homologous ethers, can also advantageously be used in some applications, especially where particular properties such as lower solidification points are required. Mixtures of polyphenyl ethers in which the non-terminal phenylene rings are linked through oxygen atoms in the meta and para positions have been found to be particularly suitable to provide compositions with wide liquid ranges. Of the mixtures having only meta and para linkages a preferred polyphenyl ether mixture of this invention is the mixture of bis(phenoxyphenoxy)benzenes wherein the non-terminal phenylene rings are linked through oxygen atoms in the meta and para position, and composed by weight of about 65% m-bis[rn-phenoxyphenoxy]benzene, 30% m-[(m-phenoxyphenoxy) (p phenoxyphenoxy) ]benzene and m-bis (p-phenoxyphenoxy)benzene. Such a mixture solidifies at below room temperature (that is, below about 70 F.) whereas the three components solidify individually at temperatures above normal room temperatures.

The aforesaid polyphenyl ethers can be obtained by known procedures such as, for example, the Ullmann ether synthesis, which broadly relates to ether-forming reactions wherein alkali metal phenoxides such as sodium and potassium phenoxide are reacted with aromatic halides such as bromobenzene in the presence of a copper catalyst such as metallic copper, copper hydroxides, or copper salts.

The above-discussed polyphenyl ether base fluids are especially thermally stable members of the class of base fluids which are oxygenated carbonaceous materials (consisting of carbon, hydrogen and oxygen atoms).

The high temperature base fluids employed in the composition of this invention may also comprise an oxygenated carbonaceous base fluid which is a synthetic ester base fluid. These are fluids of lubricating viscosity and thermally stable to at least about 400 R, which are esters of alcohols containing at least 4 carbon atoms and which generally contain more than one ester group. They may be esters of polyhydric alcohols, of polybasic acids, or both.

The stated synthetic esters are generally aliphatic in nature, as distinguished from the essentially aromatic nature of the polyphenyl ethers, and their properties and response to additives have correspondingly been found to be usually of a different kind. Unexpectedly, however, the presently contemplated metallic additives have been found to provide significant improvement in the oxidation resistance of the stated ester type of base fluid also. Thus it appears that compositions comprising an adjuvant amount of a metal compound as defined above combined with a high temperature lubricant base fluid which, broadly, is an oxygenated carbonaceous base fluid are novel and Valuable products with useful properties, and this invention extends to the provision of the stated general class of compositions.

Ester fluids with particularly advantageous low temperature viscosity properties, which flow readily at temperatures as low as 30 F., are provided by the diesters of dibasic acids. Ester lubricants of the dib asic acid ester type are illustrated by diesters of long chain dicarboxylic acids like azelaic acid with long-chain branched primary alcohols of the C to C range. The synthetic ester lubricants also frequently include the esters of long chain monobasic acids such as pelargonic acid with glycols such as polyethylene glycols. Complex esters are also formed by linking dibasic acid half esters through a glycol such as dipropylene glycol, a polyethylene glycol of 200 molecular weight, and so forth. Permutation and combination of these methods of forming polyester type lubricant fluids have been reported to be valuable and also, it is common practice to achieve desired properties in the ultimate base fluid by blending ditferent polyester products. Simple esters providing suitable fluids can be exemplified, for example, by bis(2-methylbutyl) sebacate, bis(1-methyl-4-ethyloctyl) sebacate, bis(2 ethylhexyl) sebacate, dipropylene glycol dipelargonate, the diesters of acids such as sebacic, azelaic and adipic acid with complex C -C primary branched chain alcohols such as those produced by the oxo process, polyethylene glycol 200 bis(2-ethylhexyl sebacate), diisoamyl adipate, 1,6 hexarnethylene glycol di(2-ethylhexanoate), bis(dimethylamyl) azelate and so forth.

Ester fluids with particularly good high temperature oxidation resistance are provided by neopentyl polyol esters. The alcohols from which these esters are derived have the carbon structure of neopentane, with a central carbon atom surrounded by 4 substituent carbon atoms. In cluded in the neopentyl polyols are neopentyl glycol, trimethylolethane, trimethylolpropane and pentaerythritol. Generally, the base fluids comprising neopentyl polyol esters are the esters with monocarboxylic acids. Such esters are generally more oxidatively and thermally stable than the dibasic acid esters. The useful esters of the neopentyl polyols include, for example, the esters of trimethylol propane, neopentyl glycol and pentaerythritol with normal, branched chain and mixed acids having chain lengths varying from C to C Thus, an illustrative series of esters are trirnethylolpropane tri-n-pelargonate, trimethylolpropane tricaprate, trimethylolpropane tricaprylate, the trirnethylolpropane triester of mixed octanoates, and the like.

For further description of still other ester fluids adapted for use as lubricant base stocks and useful in the provision of the blends of this invention, reference may be made, for example, to the discussion in Gunderson et al., Synthetic Lubricants (Reinhold, 1962).

The base fluid in the present compositions may consist essentially of a polyphenyl ether base fluid alone, a synthetic ester base fluid alone, or a combination of the polyphenyl ether with a synthetic ester base fluid. The polyphenyl ethers are not generally miscible with other base fluids: they do not dissolve more than about 5% by weight mineral oil, for example. Attempts to blend silicones with the phenyl ether base fluids have shown that only a few of this class of fluids are miscible with the polyphenyl ethers, and then to a limited extent. However, it has been found that the polyphenyl ethers can be combined with other oxygenated carbonaceous base fluids to provide homogeneous fluids having advantageous properties.

A deficiency of the polyphenyl ether base fluids having exceptional thermal and oxidative stability, as exemplified by the bis(phenoxyphenoxy)benzenes discussed above, is lack of fluidity at low temperatures. The fluid range of these materials is unusually wide, encompassing the range from below F. to above 800 F. However, the pour point of certain of these particularly stable fluids is above 0 F., whereas for lubricant use, for example, ability to flow down to temperature climate winter temperatures such as 0 F. is desirable. It has been found that compositions comprising combinations of ester base fluids and the polyphenyl ethers can be provided which have the desired fluidity at low temperatures.

The lubricant fluids which have been found to blend with the phenyl ethers of good thermal and oxidative stability include various esters. It is particularly desirable to provide blends having thermal and oxidative stability at least approaching the stability of the polyphenyl ethers. In this connection, especially valuable base fluids have been found to be provided by combinations of a polyphenyl ether with a neopentyl alcohol ester. These compositions possess both fluidity at low temperature and stability at elevated temperatures.

The preferred polyphenyl ethers for use in this connection are the bis(phenoxyphenoxy)benzenes, of the composition C H O-(C H O) C H where each C H is a phenyl and each (l -H is a phenylene radical. Those with the ether linkages between benzene rings in meta positions, partly or wholly, are especially preferred. The stated neopentyl esters are esters of neopentyl alcohols such as pentaerythritol, trimethylolethane, trimethylolpropane and neopentyl alcohol with straight chain, branched chain and mixed C -C acids such as n-heptanoic and neoheptanoic acid.

Compositions of the stated valuable nature are provided by combining 25-75 weight percent of the ester base fluids with 7525 weight percent of the polyphenyl et-hers.

As noted hereinabove, additive activity and particularly lubricity-improving additive activity is usually not found to be general to dflerent classes of lubricant base fluids. However, as will appear from the examples hereinafter, compositions comprising the presently employed organotitanium salts have unexpectedly been found to possess improved properties compared to the base stock alone with base oils of diverse kinds. So far as is known, the presently provided composition-s, consisting essentially of an organotitanium salt of the above-described nature and a base oil of lubricating viscosity which remains in the liquid phase at least up to about 500 F., are novel materials. Thus in its broader aspects, this invention relates to provision of compositions of the stated scope, using various base stocks of the stated description. For example, the base stock may be a hydrocarbon oil, a siliconcontaining oil, a fluorinated oil, and so forth.

Illustrative of contemplated hydrocarbon lubricant base fluids are the aromatic hydrocarbons, particularly condensed ring structures such as biphenyl, alkylbiphenyls such as monoand diisopropylbiphenyl, and terphenyls, quarterphenyls, the alkyl derivatives of these polyphenyls such as dimethylterphenyl, and the like. Hydrogenated derivatives of these aromatic hydrocarbons, including alicyclic rings and alkylated alicycli-c rings, have also been observed to possess fair stability under high temperature stress conditions. Mineral oils, paraffinic and naphthenic, can also be provided wit-h substantially improved high temperature stability as compared to the less refined oils in common use under less severe conditions, by superrefining. Super-refining is the removal or substantial reduction of the polar impurities, unsaturates and unstable hydrocarbon structures by exhaustive hydrogenation, severe acid treatment, adsorption, or a combination of these processes. The effects includeimprovement in thermal stability and metal corrosion tendencies, dirt formation and pressure buildup due to decomposition as compared to conventionally refined mineral oils. Oxidation rates at 500 F. are approximately the same for the superrefined mineral oils as for the ester lubricants. Useful mineral oils for lubricant compositions are, as is known in the art, the petroleum products boiling at temperatures above the kerosene range. A typical mineral oil base for extreme pressure lubrication will be characterized by a viscosity of 35-350 Saybolt Universal Seconds at 212 F., a viscosity index in the range of from 25 to +150 and a flash point of between about 275 and 600 F.

Silicon-based high-temperature lubricant fluids are exemplified, for example, by silanes such as n-dodecyl tri-ndecyl silane and diphenyl di-n'dodccyl silane; the silicone polymer fluids such as dimethyl silicone and methyl phenyl silicone polymers, and disiloxanes and tetraalkyl orthosilicate esters such as di-tert-butyl di-Z-ethylhexyl orthosilicate, l,3-di-tert-butoxy-1,1,2,2-tetra(2-pentoxy) disiloxane, tetra(methylphenyl) silicate, tetraphenyl silicate, tetra(2-ethylhexyl) silicate, and so forth.

Illustrative of fluorine-containnig base fluids are fluorinated esters like bis(perfiuoroamyl)phthalate, bis(perfluorohexyl) 3-methylgultarate, and 1,1-H-nonafluoropentyl nonafluoropentanoate; and the polymers of chloro- 10 trifluoroethylene, for example with average molecular weights of about 500-1000, and so forth.

The compositions of this invention will consist essentially of a major proportion of the base fluid and a minor proportion of the organotitanium additive, when formulated for use. In general, the concentrations to be employed for eflective improvement of the base fluid properties by the organotitaniurn additive will be between about 0.01% and 10.0% by weight of the fluid. Particular effective amounts depend on the nature of the individual additive and of the ether fluid. In most cases the ability of the agent with respect to extreme pressure lubrication improvement increases as the concentration is increased, whereas lowering the concentration sometimes enhances antioxidant effects. For purposes of supplying additive concentrates, adapted for convenient formulation of finished lubricant compositions, useful compositions may comprise up to about 1:1 weight ratio of the additives of this invention and the polyphenyl ether base fluid. In any case, at least an adjuvant amount suflicient to produce an improvement in at least one of the lubricant properties of the base fluid will be employed. Whether or not the desired adjuvant effect is obtained is readily determined by use of conventional testing procedures known to those skilled in the art.

It will be appreciated that the compositions of this invention, in addition to the polyphenyl ether base fluid and the organotitanium compound, may additionally include any of a wide variety of further additives. For example, these may include sludge inhibitors and detergents such as the oil-soluble petroleum sulfonates, to loosen and suspend products of decomposition and counteract their effect. Other agents such as viscosity index improvers, as exemplified by alkyl methacrylate polymers, pour point depressants, oiliness agents, and so forth, may also be present in these compositions if desired.

In the following examples, the tests employed to determine the reported adjuvant effects of the organotitanium compounds when employed with the lubricant base fluids are conducted as follows:

The anti-wear and extreme pressure lubrication characteristics of the lubricant compositions are evaluated by means of the Shell 4-Ball Extreme Pressure Tester and the Shell 4-Ball Wear Machine. These testers include four balls of stainless steel arranged in the form of an equilateral tetrahedron. The three lower balls are held immovably clamped in a holder to form a cradle in which the fourth upper ball is caused to rotate at 1200- 1800 about a vertical axis in contact with the three lower stationary balls. The contacting surfaces of the balls are immersed in the test fluid, which is held in a cup surrounding the assembly. A modified cup and heater assembly is used to evaluate lubricants at elevated temperature and provisions are made to permit testing under an inert atmosphere: see The Study of Lubrication Using the Four Ball Type Machine by R. G. Larsen, Lubrication Engineering, vol. I, pages 35-43, 59 (August 1945).

For measurement of wear, the rotating ball is rotated under a load of 40 kilograms (kg) for 1 hour at each of the temperatures for which wear scar diameters Worn in the surface of the three lower stationary balls are reported.

For determination of the extreme pressure properties in the 4-Ball EP Tester, the upper ball is rotated while the load is gradually increased by increments of 10 kg. until the balls are welded together in a 1 minute test period.

Additionally, the present compositions have been submitted to the Falex antiweld test: see the articles by VA. Ryan in Lubrication Engineering September 1946 and by S. Kyropoulos in Refiner Natural Gasoline Manufacturer, vol. 18, pages 32024- (1939), and Amer. Soc. Test. Matls. D-2, section V, Tech. K. A steel journal pin is rotated by a driving shaft at 290 r.p.m. in jaws (V-bearing steel blocks) through which a constantly increasing 1 1 load is applied, with ratchet means maintaining contact with the journal pin as it wears down during the test. The assembly is immersed in the lubricant. The load at failure due either to seizure or to wear at a rate faster than the load-increasing rate is recorded.

For determination of the antioxidant effect of the present organotitanium compounds, air is bubbled through heated samples. The percent change in (100 F.) viscosity from before to after oxidation is an index of antioxidant activity.

For a preliminary oxidation test, conditions employed are 600 F. temperature and a flow rate of 1 liter of air per hour. Samples are run in the presence and absence of metal wires (Fe, Ag, Cu, Al) as a check on the effect of such metals on the oxidation rate. In the oxidation/corrosion test, the conditions are a temperature of 400 F. and an air flow rate of 5 liters per hour. Weighed pieces of metal are included in the system to provide an index of the effect of the additive on metals which may be present in systems to be lubricated. Evaporation loss is also determined, as a measure of possible volatility of the lubricant system in use.

The invention is illustrated but not limited by the following examples.

Example 1 This example describes the extreme pressure and antiwear properties of compositions including pi-bonded organotitanium salts having sigma bonded anionic radicals containing halogen, sulfur or both, in combination with a polyphenyl ether fluid.

The pi-bonded organotitanium sales employed are as follows:

I. Dicyclopentadienyl titanium pentasulfide.

II. Dicyclopentadienyl titanium bis(trichloroacetate).

III. Reaction product of dicyclopentadienyl titanium bis- (trichloroacetate) and sodium sulfide.

Dicyclopentadienyl titanium monochloride monothiocyanate.

Dicyclopentadienyl titanium monochloride monocyanide.

Bis(methylcyclopentadienyl) titanium dichloride.

These compounds are tested as additives to a lubricant consisting of a mixture of polyphenyl ethers made up (by weight) of 65% m-bis(m-phenoxyphenoxy)benzene, 30% m-[ (m phenoxypehnoxy (p-phenoxyphenoxy) benzene and 5% m-bis(p-phenoxyphenoxy)benzene, with ratios of additive to polyphenyl ether weights as shown below.

The following table presents the results.

*Only partially soluble.

The Mean Hertz Loads calculated for the base stock and for the composition comprising dicyclopentadienyl titanium bis(trichloroacetate) are respectively 144 kg. for the base stock and 660 kg. for the composition including the titanium additive.

1 Example 2 This example further illustrates the increase in loadcarrying ability of the polyphenyl ether base stock in the presently provided compositions including organotitanium additives.

The method of test employed is the above-described Falex Shear Load Test. Four samples are run in this tester; in each sample, the base stock is the polyphenyl ether base stock described in Example 1.

(A) The base stock, free of additive;

(B) The base stock, plus 1.5 gram (g.) per g. base stock, of a freshly prepared sample of dicyclopentadienyl titanium bis(trichloroacetate)(partial solubility);

(C) The base stock plus 1.5 g. per 100 g. of base stock, of the reaction product of dicyclopentadienyl titanium bis(trichloroacetate) and sodium sulfide;

(D) The base stock and 0.5 g. per 100 g. of base stock of dicyclopentadienyl titanium pentasulfide.

The test results are as shown in the following table, Where the lubricant compositions are identified by the above-stated letters.

Falex Shear Composition: load, pounds A 500 Example 3 This example describes preparation of dicyclopentadienyl titanium pentasulfide.

Dicyclopentadienyl titanium dichloride (25.1 g., 0.1 mole) and 17.4 g. (0.1 mole) of sodium polysullide are combined in 440 milliliters (ml.) of absolute ethanol. After the exotherm (to 33 C. in 5 minutes) has ceased, and the reaction mixture temperature begins to drop, the reaction mixture is refluxed for 3 /3 hours. Then the solution is cooled to 10 C., filtered, and the solid precipitated with 440 ml. of absolute ether. The solid is then extracted with 900 ml. of boiling chloroform, providing a chloroform solution, evaporation of which leaves 13 g. of crude solid product. After recrystallization of this product from 50 ml. hot chlorofrom, 10.2 g. of dicyclopentadienyl titanium pentasulfide is obtained as a dark red solid, which gives a negative chloride but positive sulfur test by sodium fusion analysis, and gives C, H and S elemental analysis values conforming to those calculated for C10H10TiS5.

Following a similar procedure, bis(methylcyclopentadienyl)titanium pentasulfide is prepared by adding 7.4 g. (0.036 mole, calculated as Na S of sodium polysulfide, portion-wise, to 10 g. (0.036 mole) of bis(methylcyclopentadienyl) titanium dichloride slurried in 200 ml. of hot absolute ethanol. The slurry is then heated at gentle reflux for 2 /2 hours, after which the reaction mixture is cooled and filtered. The collected solids are extracted with 200 ml. of boiling chloroform, and the eX- tract evaporated to dryness, to provide 3 g. of his (methylcyclopentadienyl) titanium polysulfide as dark purple crystals, M. -170" C.

Example 4 This example describes preparation of bis(methylcyclopentadienyl) titanium dichloride.

Sodium methylcyclopentadienyl is prepared by adding g. of methylcyclopentadienyl (containing about 20% uncracked dimer), portionwise, to a suspension of 1.5 moles of sodium sand in 500 ml. of dry tetrahydrofuran, followed by stirring until only a small quantity of unreacted sodium remains, while the reaction mixture is cooled in an icewater bath. Cooling is continued while 142.5 g. (0.75 mole) of titanium tetrachloride is added slowly to the resulting solution of sodium methylcyclopetadienide. The addition requires an hour and a half. Then another 500 ml. of dry solvent is added to the reaction mixture, which is then refluxed for 3 hours. The residue remaining after removal of the solvent is subjected to prolonged extraction with toluene, providing a yield of 97 g. of bis(methylcyclopentadienyl) titanium dichloride as reddish bronze lustrous crystals M. 220-225 C. Elemental analysis values for C, H, Cl and Ti confirm the assigned composition.

Example This example describes the preparation of the reaction product of dicyclopentadienyl titanium bis(trichloroacetate) with sodium sulfide.

To a solution of 2 g. (0.008 mole) of dicyclopentadienyl titanium dichloride in 150 ml. of toluene is added 2.6 g. (0.016 mole) of trichloroacetic acid, and the mixture is gently refluxed, with stirring, for 24 hours. At the end of this period, 1.9 g. of sodium sulfide monahydrate is added, and the water of crystallization removed by azeotropic distillation of the solvent. The reaction solution is filtered hot, and the filtrate is evaporated to dryness, providing a residue of 3.1 g., M. 115-140" C., which is the stated reaction product, probably of the structure This example describes the preparation of dicyclopentadienyl titanium monochloride monocyanide.

To a solution of 4 g. (0.015 mole) of dicyclopentadienyl titanium dichloride in 160 ml. of dried toluene is added 2 g. of silver cyanide, in portions, while the mixture is stirred. The resulting slurry is then heated for 4 hours, after which the reaction mixture is filtered hot and the filtrate let cool. A precipitate comprising dicyclopentadienyl monochloride monocyanide deposits as an orange-red solid, M. 208-222 C., containing both chlorine and nitrogen per elemental analysis.

Example 7 Example 8 This example illustrates the preparation of a dicyclopentadienyl titanium dichloride reaction product with potassium sulfide.

A solution of 0.5 g. (0.002 ml.) of dicyclopentadienyl titanium dichloride in 150 ml. of acetone is added to a slurry of 0.22 g. (0.02 ml.) of potassium sulfide in 50 ml. of acetone. The reaction mixture is heated at reflux temperature for one hour and then the acetone solvent is removed by distillation until the mixture has been reduced to /3 of its volume. Xylene is added to restore the original volume of 150 ml., and the solution is filtered hot. The filtrate is evaporated down to provide a solid residue which is the material identified herein as the reaction product of dicyclopentadienyl titanium dichloride and potassium sulfide.

Example 9 This example describes preparation and properties of a lubricant composition which is a solution of a pibonded organotitanium sulfide in an oxygen-containing base fluid of the ester type.

A solution is prepared of dicyclopentadienyl titanium pentasulfide in pentaerythritol tetracaproate in a concentration of 0.5 g. of the sulfide per 100 m1. of the base fluid.

This is subjected to the above-described 400 F. oxidation corrosion test. Whereas the stated ester base stock, in the absence of additives, exhibits a 1.60 weightpercent evaporation loss and a viscosity change (centistokes (cs)., F.) of 48% in this test, the lubricant composition comprising the sulfide additive undergoes only an 0.10 weight-percent evaporation loss, and the viscosity increases by only 34%. The weight change in the aluminum and titanium washers immersed in the lubricant composition during the test is negligible (+0.06, +0.03 mg. per sq. cm.).

For evaluation of the ability of the additive to increase the load-carrying ability of the base stock and improve wear characteristics, the tests employed are the Shell 4-Ball Extreme Pressure and Shell 4-Ball Wear Test described above. The composition comprising the organotitanium additive is prepared by dissolving dicyclopentadienyl titanium pentasulfide in pentaerythritol tetracaproate base stock in a concentration of 0.5 g. per 100 g. of base stock. In the extreme pressure test, the weld point of the base stock Without additive is kg., while the weld point for the composition in which the base stock contains dissolved dicyclopentadienyl titanium pentasulfide is 180 kg. Measurement of the wear scar diameter gives the following values (scar diameter in mm.)

This example illustrates the effect of the dicyclopentadienyl titanium dichloride reaction product with potas sium sulfide on the lubricating properties of the abovedescribed ester base fluid.

A lubricant composition is prepared by combining the stated reaction product with pentaerythritol tetracaproate in a concentration of 0.5 g. of the additive per 100 g. of the ester base fluid. The Shell 4-Ball EP weld point of this composition is 240, and the wear scar diameter is 1.08 mm. at 400 F, whereas for the untreated base stock the EP value is 120 kg. and the Wear scar diameter at 400 F. is 1.74 mm.

Example 11 This example describes preparation and properties of a lubricant composition which is a solution of a pibonded organotitanium chloride in the oxygen-containing base fluid of the ester type employed in the preceding examples.

A solution is prepared by combining 100 ml. of pentaerythritol tetracaproate with 0.5 g. of dicyclopentadienyl titanium dichloride, and the Shell 4-Ball EP Weld point is determined to be -160 kg. as compared to the untreated base stock value of 120 kg.

Example 12 This example describes properties of pi-bonded organotitanium chlorineand sulfur-containing compounds in solution in another oxygen-containing ester type fluid.

Lubricant compositions as identified hereinafter in this example are subjected to the Shell 4-Ball extreme pressure and wear tests described above. The compositions tested included the following organotitanium compounds, in the concentrations stated (g./100 g. base stock), in a base fluid which is a trimethylolpropane ester (MLO 7384), the tri-enanthate.

G. A. Bis(methylcyclopentadienyl)titanium pentasulfide 0.5 B. Bis(methylcyclopentadienyl)titanium dichloride 0.5 C. Dicyclopentadienyl titanium bis(tric-hloroacetate) 0.5

D. Dicyclopentadienyl titanium chloride thiocyanate 0.25

E. Dicyclopentadienyl titanium bis(decylxanthate) 2.0 F. Dicyclopentadienyl bis(didecyldithiophosphate) 5.0

The results of the tests are shown in the following table.

Shell l-Ball Wear Scar Diameter at Weld Point 40 kg, mm. Additive kg 167 F. 400 F. 000 F.

As will be evident from the foregoing figures, the dithiophosphate compound, which raises the weld point to the greatest extent, also maintains the wear scar diameter at less than 1 millimeter at all three temperatures. Generally, antiwear additives are specific to l or 2 temperatures, and do not exert their protective effects over a wide temperature range.

Example 13 This example describes preparation of the additive identifed as dicyclopentadienyl titanium bis(decylxanthate).

A slurry of 2.5 g. (0.01 mole) of dicyclopentadienyl titanium dichloride and 2.72 g. (0.02 mole) of potassium decylxanthate in 120 ml. of toluene is heated at gentle reflux for 6 hours and filtered hot. Reducing the filtrate to dryness leaves a three gram residue which constitutes the material employed in the herein-reported tests of lubricating properties.

Example 14 This example describes lubricating characteristics of compositions consisting of a mineral oil and pi-bonded organo-titanium salts.

Lubricant compositions are provided by dissolving (A) bis(methylcyclopentadienyl titanium sulfide, (B) the reaction product of dicyclopentadienyl titanium bis(trichloroacetate) and sodium sulfide prepared as described in Example 5, and (C) the reaction product of dicyclopentadienyl titanium dichloride and potassium sulfide prepared as described in Example 8, respectively, in portions of a naphthenic white oil described as MLO-7357, which has a pour point of -18 F, viscosity 80.57 cs. at 100 F., 8.51 cs. at 210 F., in additive concentrations of 0.25 g. ((A) and and 0.50 g. (C) per 100 g. of base oil.

Without additive, this oil has a weld point of 120 kg. and produces wear scar diameters of 1.60 mm. at 167 F, 2.65 mm. at 400 F. and 3.59 mm. at 600 F. The composition comprising the bis(methylcyclopentadienyl) titanium pentasulfide has a weld point of 140 kg. and the wear scar diameter is 0.64 mm. at 167 F., 1.33 mm. at 400 F., and 2.79 mm. at 600 F. The composition comprising the reaction product of the organotitanium trichloroacetate compound and sodium sulfide has a weld point of 150 kg., and the wear scar diameter is less than 1.0 mm. at 167 and 400 F; 0.77 mm. and 0.74 mm. respectively. The wear scar diameter of the lubricant composition including reaction product (C) is also below T0 1.0 mm. at these temperatures: 0.87 mm. at 167 F. and 0.80 mm. at 400 F.

While the invention has been described with particular reference to various specific preferred embodiments thereof, it is to be appreciated that modification and variations can be made without departing from the scope of the invention, which is limted only as defined in the appended claims.

What is claimed is:

1. A composition consisting essentially of (1) a base oil of lubricating viscosity which remains in the liquid phase up to at least about 500 F. and (2) a pi-bonded organo-titanium salt having a univalent carbocyclic radical pi-bonded to the titanium and an anion containing at least one element selected from the class consisting of sulfur and chlorine, in an amount at least sufficient to improve the lubricating characteristics of said base oil.

2. The composition of claim 1 wherein said base oil is an oxygenated carbonaceous compound selected from the class consisting of polyphenyl ether base fluids and synthetic ester base fluids of lubricating viscosity and thermally stable to at least about 400 F., which are esters of alcohols containing at least 4 carbon atoms.

3. The composition of claim 2 wherein said base oil is a polyphenyl ether base fluid.

4. The composition of claim 3 wherein said pi-bonded organotitanium salt is a dicyclopentadienyl titanium sal in which the anion contains sulfur.

5. A lubricating composition consisting essentially of a polyphenyl ether base oil of lubricating viscosity which remains in the liquid phase up to at least about 500 F. and a dicyclopentadienyl titanium sulfide wherein said cyclopentadienyl ring substituents are selected from the class consisting of hydrogen and alkyl radicals of from 1 to 6 carbon atoms, in an amount at least sufficient to improve lubricating characteristics of said base oil.

6. A lubricating composition consisting essentially of a polyphenyl other base fluid of lubricating viscosity which remains in the liquid phase up to at least about 500 F. and dicyclopentadienyl titanium pentasulfide, in an amount at least suificient to improve the lubricating characteristics of said base fluid.

7. The lubricating composition of claim 3 wherein said organotitanium salt has an anion containing chlorine.

8. A lubricating composition consisting essentially of a polyphenyl ether base fluid of lubricating viscosity which remains in the liquid phase up to at least 500 F. and a dicyclopentadienyl titanium bis(chloroacetate) wherein said cyclopentadienyl ring substituents are selected from the class consisting of hydrogen and alkyl radicals of from 1 to 6 carbon atoms, in an amount at least sufiicient to improve the lubricating characteristics of said base fluid.

9. A lubricating composition consisting essentially of a polyphenyl ether base fluid of lubricating viscosity which remains in the liquid phase up to at least 500 F. and dicyclopentadienyl titanium bis(trichloroacetate), in an amount at least sufiicient to improve the lubricating characteristics of said base fluid.

10. The composition of claim 3 wherein the organotitanium salt combined with said oxygen-containing lubricating base fluid is a pi-bonded organotitanium chloride.

11. A lubricating composition consisting essentially of a polyphenyl ether base fluid of lubricating viscosity which remains in the liquid phase up to at least about 500 F. and dicyclopentadienyl titanium dichloride, an an amount at least sutficient to improve the lubricating characteristics of said base flud.

112. A lubricating composition consisting essentially of a polyphenyl other base fluid of lubricating viscosity which remains in the liquid phase up to at least 500 F. and bis(methylcyclopentadienyl titanium dichloride, in an amount at least suificient to improve lubricating characteristics of said base fluid.

Where (C H is the cyclopentadienyl ring and x is an integer, in an amount at least sufficient to improve the lubricating characteristics of said base fluid.

1 8 References Cited by the Examiner UNITED STATES PATENTS 6/1960 Diamond 252-33.6 11/1960 Young 252-42.7 5/1961 Thomas et a1 260-4295 4/1962 Giddings 260-4295 7/ 1962 Sloan et a1. 260-4295 FOREIGN PATENTS 11/1957 Great Britain.

1/1961 Great Britain.

DANIEL E. WYMAN, Primary Examiner. 

1. A COMPOSITION CONSISTING ESSENTIALLY OF (1) A BASE OIL OF LUBRICATING VISCOSITY WHICH REMAINS IN THE LIQUID PHASE UP TO AT LEAST ABOUT 500*F. AND (2) A PI-BONDED ORGANO-TITANIUM SALT HAVING A UNIVALENT CARBOCYCLIC RADICAL PI-BONDED TO THE TITANIUM AND AN ANION CONTAINING AT LEAST ONE ELEMENT SELECTED FROM THE CLASS CONSISTING OF SULFUR AND CHLORINE, IN AN AMOUNT AT LEAST SUFFICIENT TO IMPROVE THE LUBRICATING CHARACTERISTICS OF SAID BASE OIL. 